Re: dnsmasq dhcp failure

Hi Folks

Am 29.08.2022 um 00:31 schrieb marko via leaf-user:
> Hi ET,
> 
> I have run leaf for a very long time, normally on fast hardware with plenty of
> memory.
> 
> I've never seen dnsmasq not serve requests or allocate leases.
> 
> I think dnsmasq fits the smaller network that is a bit complex scenario very
> well.  Making it more complex would be a mistake as would making it more like
> commodity routers which have many functions now.

I can show now that with assigning a fixed address to a win10 client I 
can connect to the uplink LEAF system and the internet correctly. So 
obviously the dhcp request is _not_ handled correctly.

Once connected to the LEAF box I see the folloging on the internal interface

SALT# tcpdump -i br0 port 67
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on br0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
11:51:55.058168 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 324
11:51:55.061890 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 324
11:52:00.059480 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 324
11:52:04.063118 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 318
11:52:09.065633 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 318
11:52:14.068486 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 318
11:52:19.077023 IP .bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request 
from 34:46:ec:b2:ab:e7 (oui Unknown), length 318


So again, it looks like dhcp requests are coming in but are not replied to.

So for completeness I copy the configuration here

SALT# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
group default qlen 1000
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
        valid_lft forever preferred_lft forever
2: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group 
default qlen 1000
     link/ether 12:66:bb:45:54:68 brd ff:ff:ff:ff:ff:ff
3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast 
master br0 state UP group default qlen 1000
     link/ether 00:0d:b9:04:6e:d8 brd ff:ff:ff:ff:ff:ff
4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state 
UP group default qlen 1000
     link/ether 04:f0:21:17:32:8e brd ff:ff:ff:ff:ff:ff
     inet 192.168.1.69/24 brd 192.168.1.255 scope global dynamic 
noprefixroute wlan0
        valid_lft 2522sec preferred_lft 2072sec
5: wlan1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue 
master br0 state UP group default qlen 1000
     link/ether 04:f0:21:17:32:8b brd ff:ff:ff:ff:ff:ff
6: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state 
UP group default qlen 1000
     link/ether 00:0d:b9:04:6e:d8 brd ff:ff:ff:ff:ff:ff
     inet 192.168.217.1/24 scope global br0
        valid_lft forever preferred_lft forever

Restarting shorewall took forever so I looked at the processes running 
and I found that dnsmasq is quite prominent in the CPU score.

Mem: 47060K used, 9576K free, 2448K shrd, 0K buff, 2448K cached
CPU: 97.2% usr  1.3% sys  0.0% nic  0.0% idle  0.0% io  0.0% irq  1.3% sirq
Load average: 2.35 2.55 1.87 2/55 8490
   PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND
  1724     1 nobody   R     1200  2.1 97.4 /usr/sbin/dnsmasq
  8330  8283 root     R     1320  2.3  1.5 top
  8281  1989 root     S     4136  7.2  0.5 sshd: root@pts/2
  2005     1 root     S      968  1.7  0.1 /usr/sbin/cron
  8380     2 root     IW       0  0.0  0.1 [kworker/u2:0-ph]
  1628     1 root     S    12600 22.1  0.0 /usr/sbin/rsyslogd

These systems used to run fine in the past so I am suspicious that newer 
linux software starts to become bloatware just like on the winblows side.

I definitely will replace dnsmasq and see if a combination of dnscache 
and dhcpd works better.

cheers

ET

------------------------------------------------------------------------
leaf-user mailing list: [email protected]
https://lists.sourceforge.net/lists/listinfo/leaf-user
Support Request -- http://leaf-project.org/